Tinsel wire connector



p 1966 c. E. MICHAELY 3,274,530

TINSEL WIRE CONNECTOR Filed Nov. 5, 1963 3 Sheets-Sheet l Sept. 20, 1966c. E. MICHAELY TINSEL WIRE CONNECTOR 5 Sheets-Sheet 2 Filed Nov. 5, 1963p 20, 1956 c. E. MICHAELY 3,274,530

TINSEL WIRE CONNECTOR Filed Nov. 5, 1963 5 Sheets-Sheet 3 United StatesPatent M 3,274,530 TINSEL WIRE CONNECTOR Charles E. Michaely, 9132Greenwood Ave., Des Plaines, Ill. Filed Nov. 5, 1963, Ser. No. 321,492 4Claims. (Cl. 339-97) This invention pertains to electrical connectorsand more particularly, to means for making an electrical connection orelectrical connections to a tinsel wire or to a plurality of such wires.The invention especially pertains to telephones and the cord containingtinsel wires, now almost without exception a stretchable coil cord,between the hand set and the base portions of the phone, though theinvention, in other than some of its more specific aspects, is verydefinitely not restricted to the same.

A primary objective of the invention is to provide a connector formaking an electrical connection directly to an insulated tinsel wirehaving its insulation substantially intact to the end thereof withoutdamaging the tinsel conductor of the wire.

Another very important object of the invention is to provide a connectorfor making an electrical connection directly to an insulated tinsel wirehaving its insulation substantially intact to the end thereof withoutdamaging the tinsel conductor of the wire.

Another very important object of the invention is to provide a connectoras above set forth which will reliably make a good electrical connectionto even very old wire having a thick coating or layer of insulatingoxide, sulphide, or other undesired matter.

Another and much more specific object of the invention is to provide atelephone coil cord having a connector portion at each end thereof whichportions and the wires of the cord attached thereto are insertablethrough an opening in the microphone end of the hand set and an openingin the side of the base, respectively, of a telephone into electricalmaking engagement of the wires with contact means of a connector portionin the hand set and contact means of a connector portion in the base,respectively, of the telephone as above indicated for the connectionmaking, which first named portions also being most easily removable fromthe electrical making engagement of the wires thereof with the contactmeans of the second named portions, respectively.

Other objects, advantages and features of the invention in its variousaspects and forms will appear in the course of reading and consideringthe following description, in conjunction with the accompanying drawingin which:

FIG. 1 is a perspective view of a telephone employing a preferred formof the invention;

FIG. 2 is an enlarged perspective view of the upper connector andmicrophone casing combination contained within the speaking end of thehand set of the telephone,

which latter is indicated in phantom lines;

FIG. 3 is an enlarged side elevational view of the plug or femaleportion of the upper connector in the FIG. 2 position but with the restof the connector being omitted for the purposes of illustration, part ofthe hand set of the telephone being shown in phantom lines and part ofsaid portion being shown broken away;

FIG. 4 is a sectional view taken on line 44 in FIG. 3 and in thedirection of the arrows;

FIG. 5 is an enlarged end elevational view of the connector portionshown in FIG. 3 as seen from the right in that figure;

FIG. 6 is an enlarged perspective view of the inner wire holding membershown by itself in an unstressed condition;

FIG. 7 is an enlarged fragmentary sectional view taken 3,274,530Patented Sept. 20, 1966 on line 77 of FIG. 5 and in the direction of thearrows;

FIG. 8 is an enlarged cross sectional view taken on line 88 in FIG. 7and in the direction of the arrows;

FIG. 9 is a front elevational view of the socket or female portion ofthe upper connector with a portion being broken away to show theinterior;

FIG. 10 is a bottom plane view of the portion shown in FIG. 9;

FIG. 11 is an enlarged fragmentary perspective view of the upper rearportion of the connector portion shown in FIG. 9 showing one of thecontacts in the process of being inserted and anchored in said portion;

FIG. 12 is an enlarged sectional view taken along lines 1212 of FIG. 9and in the direction of the arrows;

FIG. 13 is a greatly enlarged perspective view of the forward endportion of one of the four contacts of the connector portion shown inFIG. 9, such end portions of all of the contacts being the same;

FIG. 14 is an enlarged fragmentary longitudinal center sectional viewsimilar to FIG. 7 but showing a portion of the socket part with one ofits contact members just touching the insulation of one of the tinselwires and ready to start its insertive contact making movement relativeto the plug portion;

FIG. 15 is a more greatly enlarged view similar to FIG. 14 but showingthe contact member introduced to some extent;

FIG. 16 is a greatly enlarged fragmentary cross sectional view taken online 1616 of FIG. 15 and in the direction of the arrows and showing thepaths of plastic insulation flow taking place ahead of the cuttingplane;

FIG. 17 is a greatly enlarged fragmentary longitudinal center sectionalview at right angles to the FIG. 15 showing but with the contact memberbeing shown in a more fully inserted position than that shown in FIG. 15and with the paths of plastic insulation flow being indicated by meansof arrows;

FIG. 18 is a greatly enlarged fragmentary sectional view taken on lines18-18 of FIG. 17 and in the direction of the arrows and with the pathsof plastic insulation flow being indicated by means of arrows;

FIG. 19 is a view similar to FIG. 17 but at a higher elevation showingthe exterior of the plug member under the collar and of the wire andcontact member and with the plastic flow of the insulation beingindicated by arrows;

FIG. 20 is a fragmentary sectional view taken along lines 20-20 of FIG.19 and in the direction of the arrows and with the plastic fiow beingindicated by arrows;

FIG. 21 is a view similar to FIG. 15 but with the contact member beingshown fully inserted and with forces which maintain the member in theproper disposition while inserted being indicated by arrows;

FIG. 22 is a cross sectional view taken on lines 2222 of FIG. 21 and inthe direction of the arrows showing the static condition of the plasticinsulation when the electrical connection is made.

Referring to the drawing figures in detail and first to FIGS. 1 through22, the numeral 1 designates the base portion of the telephone on whicha hand set 2 is normally cradled or supported when not in use. Aflexible and extendable coil cord 4 extends between the speaking end 5of the hand set and the lower part of the base portion 1 of the phone.The upper connector and microphone casing combination, shown in thefully assembled, electrical connection making condition in FIG. 2,comprises a plug or female portion generally designated 9 and a socketor male portion including the microphone casing generally designated 10.

The plug portion 9 comprises a rigid member generally designated 11 ofelectrically insulative material such as 3 suitable plastic having anopening 12 extending therethrough along the axis of the member. Theopening 12 has a forwardly converging frusto-conical surface 13 in themid and forward portion thereof while the opening has a cylindricalsurface 14 extending rearwardly of the conical surface to the rearlimits of the plug member 11. The latter member is cylindrical in outerconfiguration between the ends thereof except for a pair of opposite,coextensive flat, surfaces 16 forming a pair of forward fiat shoulderportions 17 at the rear ends thereof and a rearward reduced portion 19of cylindrical form forming an annular shoulder 20 at the forward endthereof. The member 11 has a flat forward inclined face 22 which isdisposed in a generally flush relation with the end surface 23 of thehand set of the telephone in the position of the member shown in FIG. 2.

The member 11 is also provided with four rectangular grooves 24extending from the rearward face 25 of the member forwardly as far asthe annular shoulder 20. The upper grooves 24 are disposed at 45 degreesfrom and on opposite sides of a vertical plane passing through the axisof the member while the lower grooves 24 are disposed at 30 degrees fromand on opposite sides of such plane to provide a polarizing arrangementfor engagement of the four contained tinsel wires with the four contacts26 and 27 of the socket portion 10 which contacts are similarly arrangedat the same angularity to a vertical plane passing.

through the axis or longitudinal center line of the portion, thus topermit but a single electrical connection making relation between theportions 9 and 10 in the assembled condition shown in FIG. 2. The member11 is further provided with four identical notches 29 extending for-.little less width than a tinsel wire and continuing straight forwardlyfrom the grooves 24, respectively.

The coil cord 4, which comprises an outer sheathing 35 of flexibleresilient material such as a suitable plastic and four insulatedflexible tinsel wires 36 therewithin, extend within the central opening12 of the plug member :11 and also a combination tinsel wire holdingmember and coil cord strain relief member generally designated 38 andnow to be described.

The member 38 has an outer cylindrical wall or surface 39 extending fromthe front to the rear thereof in the unstressed, unmounted condition ofthe member shown in FIG. and an inner cylindrical surface 40 extendingfrom the rear forwardly and terminating in an annular shoulder v41 inthe condition of the member shown in FIG. 5. An

inwardly converging frusto-conical surface 42 extends rearwardly fromthe front end of the device terminating close to the shoulder 41. Fourequally spaced, identical parallel slots 44 extend most of the lengthrearwardly from the front of the device to provide four resilientsegments or portions 45. The conical surface 42 together with theshoulder 41 form four inwardly projecting portions 46, one on each ofthe segments 45, for a purpose to appear shortly.

The plug portion 9 is also provided with a ring like collar 49 formed ofrigid, electrically insulative material such as suitable plastic whichmember extends around the cylindrical surface 19 of the member 11 fromthe rear face 25 of the latter to the annular shoulder 20 of the same inthe mounted relation of the parts. Although the inner diameter of thecollar 49 is such as to cause the collar to remain on the plug member 11in engagement with the cylindrical surface 19 thereof both prior to aswell as after the securement of the four tinsel wires 36 within the plugportion, such inner diameter may be somewhat larger so that the collar49 will not so remain on the plug member 1.1 prior to such attachment ofthe wires but is retained thereon, even out of contact with thecylindrical surface 19 of the member, by the four tinsel wires 36received within their respective grooves 24 of the member 11 whenthereon and cannot be retained thereon prior to the mounting of thecollar over the four tinsel wires 36 and which is retained on the member11 only by the resiliency of the squeezed tinsel wires interposedbetween thte same and the member 11 as well as a collar of thedimensions to which reference was made above and represented in thedrawing figures.

For attachment or securement of the end portion of the coil cord 4 ofthe telephone to the plug portion 9 of the upper connector, the coilcord which comprises the outer sheathing 3'5 and the four containedtinsel wires 36 is inserted through the central opening 12 of the plugmember 11 from the front thereof and pulled entirely through thatmember. The entire coil cord is then inserted through the centralopening 47 of the holding member 38, between the portions 46 thereof,from the front and entirely through the open center of that member. Itis pointed out in this connection that the opening 47 between theinwardly projecting portions 46 of the segments 45 of the member 38 isof a smaller size than the outer diameter of the outer sheathing 35 ofthe coil cord 4, thus to cause the segments 45 to flex outwardly whenthe coil cord is passed through the opening 47 of the member 38. Theouter sheathing 35 of the coil cord 4 is next cut away back from theends of the four tinsel wires 36 a substantial and suitable distance ifsuch cutting of the sheathing has not already been accomplished prior tothis time. The entire cord 4 is next pulled for-wardly through theholding member 38 until the end of the outer sheathing 35 of the cord issomewhat inwardly of the rear end of the .member 38 as can best beappreciated from viewing the semi-cylindrical forward surfaces thereofwith as much as possible of the surplusage or looseness of the Wireseliminated and the wires therebrought around and placed within therespective longitudinal slots 24 of the plug member 11, as can best beappreciated from FIG. 7. Any

extra lengths of the tinsel wires may be placed within the respectivegrooves 33 if they are not too excessive in length or the same may betrimmed oil. The collar 49 is then moved forwardly onto over the outerreduced cylindrical portion 19 of the plug member 1 1 the four tinselwires 36 in the grooves 24 of the member into the mounted position shownin FIGS. 3-7, for instance, of

.the drawing. As can be seen in FIGS 5, 7' and 8, the

distances between the inside of the collar 49 and bottom or insidesurfaces of the grooves 24 is considerably less than the diameters ofthe tinsel wires 36 when in their normal round unstressed or unsqueezedconditions. Accordingly, when the collar 49 is slipped over the end ofthe plug member 1 1 and the four tinsel wires 36, the latter becomesconsiderably squeezed between the collar and bottom or inner surfaces ofthe grooves 24 of the member 11. This squeezing retains the collar 49 aswell as the fourtinsel wires firmly in place. Such retention of thecollar is of course the only means of retention of the same on themember 11 where the inner diameter of the by virtual of a certaingripping of the cord by the inwardly projecting portions 46 of themember and the engagement of the ungripped sheathing 35 of the cordimmediately behind the annular shoulder of the member with the shoulder.Such forward movement of the holding member 38 relative to the plugmember 11 produced inward caming and flexture of the sectors or portions45 of the holding member by the engagement of portions 45 with thefrusto-conical surface 13 of the plug member 11 to even more stronglygrip the coil cord 4 and pull the member 38 forwardly along with thesame. The member 38 accordingly becomes very tight within the plugmember 11 to serve as a combination strain relief of the coil cord 4 andalso, most importantly, to pull the individual tinsel wires 36 into arelatively taut condition from their squeezed portions within thegrooves 24 of the plug member 11. The latter holding of the tinsel wires36 in a taut condition serves an important purpose which will appearhereinafter. It should of course be appreciated in this connection thatfriction between the frusto-conical surface 13 of the plug member 11 andthe resilient portions 45 of the holding member 38 retain the latter member in a forward mounted condition within the plug member 11 as seen inFIG. 4.

The socket or male portion of the connector comprises a member generallydesignated 53 of electrically insulative material such as a suitableplastic which member provides a forwardly opening cavity 54 forrelatively snugly receiving the assembled plug portion 9 with attachedand positioned tinsel wires 36 therewithin for the assembled relation ofthe connector shown in FIG. 2. The cavity 54 is more particularly formedby a back portion 55, and upper and lower portions 56 and 57 and twooutwardly flexible and resilient side portions 58. The two side portions58 are provided with a pair of flat, vertical, rear-converging, camsurfaces 59, respectively, which are flat, coplanar shoulder surfaces60, respectively, for outward flexure or caming of the side portionsover the round rearward portion of the plug portion 9 of the connectorduring insertion of the plug portion within the cavity 54 of the socketportion and for inward flexure of the portions 58 behind the roundrearward pont-ion of the plug member for interlocking engagement by theshoulders 60 of the side portions 58 of the socket member with theshoulder portions 17 of the plug portion. It is pointed out in thisconnection that a U shape tool may be inserted along the opposite flatsurfaces 16 of the plug portion 9 and pushed against the cam surfaces 59of the socket portion 10 to expand or outwardly flex the side portions58 thereof for the rel-ease and withdrawal of the plug portion 9 fromthe locked, electrical contact making relation with the socket portionwhenever desired. Referring to FIG. 2, the above mentioned tool can beinserted in the space which is available between the plug member 11 andthe hand set of the telephone on each side of the member. It is alsopointed out that the same release may be effected in the same manner inconnection with the lower connector portion shown in FIGS. 26 through28, the tool also being conveniently insertable from outside of thetelephone.

The socket member 53 is also provided with a lower open bottomcylindrical casing portion 62 for containing the microphone 63 shown inphantom lines in FIG. 9, the socket portion 10 further being providedwith four electrical contacts 26 and 27. These contacts have identicalforward, tinsel wire engaging, electrical contact making portions one ofwhich is shown fragmentarily in FIG. 13 and which will be consideredsubsequently.

The upper contacts 26 extend straight rearwardly through a cross-shapedopening 28 for each which relatively snugly receives the same whichcontacts extend in fiat bottom side engagement with rear surfaces 66 and67, respectively, of a rearwardly extending portion 68 of the member 53.The lower or outer edges of the contacts 26 extend along and restagainst the inner flat surfaces, re-

spectively, of raised outwardly extending portions 69 and 70,respectively, of said rearwardly extending portion of 68 to provide firmsupport together with the surfaces 66 and 67 to the contact members inthe fully assembled relation of the latter. A transversely extendingvertical wall portion 71 of the portion 68 extends rearwardly of theupwardly surfaces 66 through 70 and upwardly to some extent from thesurfaces 66 and 67 for snug fitting engage ment within the notches 73 ofthe contact members 26 when the latter are in the mounted, lockedconditions thereof shown in the case of one of the contact members atthe lower half of FIG. 11. The upper part of FIG. 11 shows the otherresilient contact 26 slightly outwardly flexed and being passed over theupwardly extending rearward wall portion 71 during insertion of thecontact through its opening 28 which extends through the rear portion 55of the socket member 53. This latter contact member is continued in itsforward movement until the notch 73 thereof registers with the upwardextending wall portion 71 whereupon the resilent contact snaps inwardlyor downwardly into the interlocked relation indicated for the othercontact in the lower half of FIG. 11. It should be obvious that thesecontacts 26 may be easily removed from the socket member 53 merely bylifting the rear portions of the contacts 26 above the rearward wallportion 71 and then moving the entire contact members, in a flexedcondition, rearwardly out of the openings 28 through the rear portion 55of the socket member. Each of the contacts 26 isconnected to aninsulated tinsel wire 76 by means of crimping an originally U shapedrear portion of the contact 77 within which the end part of insulatedwire is placed and which rearward portion 77 has a pair oflongitudinally spaced upwardly struck elements for piercing the wire andthe electrical contact with the tinsel wire upon formation of the Ushaped rear portion 77 into the cylindrical crimped condition shown inFIG. 11. It is also pointed out that the contacts 26 are identical toeach other, one of them merely being flipped over 180 relative to theother so that this can be the case, that is, so that the notch 73thereof is uppermost or innermost.

The lower two contacts 27, which are mirror images of each other, extendthrough cross shaped openings 80 in the rear portion 55 of the socketmember 53, being relatively snugly received within the same, andrearwardly from there in flat upperside engagement with the flatinclined under surfaces 81, respectively, of the rearwardly extendingportion 68 of the socket member. The contacts 27 are provided withoutwardly extending legs 83 terminating in somewhat enlarged andcentrally apertured portions 84 through which screws 85 extend forelectrical connection to spring contact members 86 and 87 within themicrophone casing 62 for electrical contact with the microphone 63 whenplaced within the casing and retained therein by a lower perforatedportion 88 of the hand set 2 of the telephone threaded receiver on therest of the hand set. Each of the screws 85 is actually threadedlyreceived within an internally threaded sleeve 89 (only one of which isshown) which is retained within the socket member 53 and also whichretains its spring finger such as 87 thereon by being enlarged at itsupper end 90 and rolled outwardly and upwardly at its lower end 91. Eachof the contact members 27 is outwardly and horizontally bent at 92 fromits downward and inwardly inclined condition, the outer flat legs 83 ofwhich contacts rest against the upper flat, horizontal coplanar surfaces93 of the socket member. These contact members may also be easilyremoved from the socket member 53 by merely removing the screws 85 andslipping the contacts out rearwardly through the openings 80 in thesocket member. To complete this part of the description, upwardlyextending, rearwardly converging walls 94 are provided from the flatsurfaces 93 of the socket member 53 along which walls the legs 83 of thelower contacts 27 continually engage along the outer edges thereof, thusto retain the contacts in their proper positions during the making ofthe electrical connections. For removal of the contacts 27 from thesocket member, the

,leg portions 83 thereof, of course, must be raised up,

flexing the contact member, over the walls 94.

Each of the contacts 26 and 27 extend forwardly of the rear wall orsurface 95 of the cavity 54 of the socket member a substantial and equaldistance therefrom. Each of the electrical contacts is longitudinally,medially slotted at 97 to form two spaced connector portions 98 and 99of the same width thereacross. The slot 97 terminates rearwardly in acircular opening 100 which facilitates the formation of the slot andserves no other function .over having the flat sidewalls of the slot 97extend all the way to the rear extremity thereof. It is also pointed outthat the slot 97 terminates at the rear thereof, by way of the circularopening 100, somewhat forwardly of the rear wall 95 of the cavity 54.

Each of the spaced portions 98 and 99 of each contact is of rectangularcross section and has inner and outer parallel faces 102 and 103, eachof said portions being of uniform cross section from the front of theslot 97 to the round opening 100 of the contact. The co-extensiveportions 98 and 99 each contain a flat lead-in surface 106.

.Each of these lead-in surfaces and also each of the inner and outerfaces 102 and 103 of the spaced portions 98 and 99 is in a verticalplane normal or at right angles to the upper and lower, flat, parallelfaces 107 and 108 of said portions.

Each of the lead-in surfaces 106 extend outwardly and forwardly from theinner faces 102 of the portions 98 and 99 at 120 degrees to form a welldefined combination insulation shearing and scraping edge extending thefull height or thickness of the contact portions 98 and 99. Thejunctures of these lead-in surfaces 106 with the upper and lower fiatfaces of the contact portions 98 and 99 are also well defined insulationshearing surfaces 113 and 114. The lead-in surfaces 106 smoothly mergeinto curved outer end surfaces 117 which latter in turn smoothly mergeinto the outer faces 103 of the contact portions. ,Each of the contactportions 98 and 99 of each of the contacts of both the upper and lowerconnectors are mirror image duplicates of each other as is believedquite evident from the drawing figures.

The height or thickness of each pair of contact portions 98 and 99 issubstantially less than the distance between the collar 49 in which thepair of contact portions is inserted, along the center of the groove andthe bottom surface 31 of the groove 19, as is quite evident from viewingFIG. 16 for instance. Moreover, the thickness of each pair of saidcontact portions is also appreciably less than the distance between thecollar 49 and bottom surface 31 of the groove 19, in which the pair ofcontact portions is inserted, along the outer portions of the groove inthe neighborhood of the outer edges or surfaces 103 of the contactportions 98 and 99 as can be appreciated from viewing FIG. 16 forinstance.

The upper and lower fiat faces of each contact extend substantiallystraight forwardly from the back surfaces 95 of the cavity 54 of thesocket member 53 substantially at right angles to the same prior toinsertion of the contact and further, the lower flat face of the contactis substantially co-planar with the bottom, flat surface 31 of thegroove 24, in which the contact is inserted, of the plug member 11before the contact is inserted in the groove, or more precisely, beforethe contact is caused to be inserted in the groove by the movement ofthe plug portion 9 farther within the socket portion 10, as can beappreciated from viewing FIG. 14. In this figure, the plug portion 9 hasbeen shown moved within the socket member 53 so that the outer surfaceof the insulation of the tinsel wire 36 just touches the lead-insurfaces 106 of the contact portions 98 and 99 on each side of thecentral slot 97 of the contact.

In FIG. 15, the plug portion 9 has been depicted as having been movedsomewhat farther within the socket member 53 to, in effect, cause thecontact portions 98 and 99 of each pair of portions to be insertedsomewhat farther within the space between the collar 49 of the plugportion and bottom of the groove thereof in which the pair of contactportions is inserted. It will be noted that the spaced contact portions98 and 99 have flexed somewhat upwardly from their support within thesocket member 53, after first eliminating what space there may bepresent, the contact portions having ridden up on the curved outersurface of the insulation of the tinsel wire, rather than appreciablycompressing the same or causing shearing thereof, until the forwardparts of the outer upper edges of the portions 98 and 99 engaged theinner cylindrical surface 121 of the collar 49 above the outer portionsof the groove 24 of the plug member as shown in FIG. 16. Furtherinsertive movement of the contact portions 98 and 99 beyond the pointwhere they first contact the surface 121 will cause cutting of theinsulation of the tinsel wire by shearing and a certain cold flow of theplastic insulation producing a considerable amount of plastic pressurebelow the forward parts of the contact portions 98 and 99 exerted orapplied upwardly .on said portions as indicated by the arrows at 124(see FIG. 15), to thencefort-h cause the forward part of the outer upperedge 120 of each contact portion to continually engage and ride alongthe inner surface 121 of the collar 49 during the rest of the insertivemovement of the contact portions and as long as the electricalconnection remains thereafter.

Although certain illustrative forms of the invention have been disclosedfor telephone use as well as general use, it should be appreciated thatmany other forms of the invention in its various aspects and areas maybe had within the general overall spirit of the invention. Accordingly,the present invention should be limited only by the terms of theappended claims read in the light of the broad overall spirit of theinvention in its various aspects and concepts.

What is claimed is:

1. A plug member for an electrical connector comprising a body memberhaving an opening therethrough, said body member having an annularportion of reduced diameter at its rearward end, said annular portionhaving a series of axially extending grooves in its outer surfaceextending from its rearward end toward its forward end, a strain reliefmember disposed within said opening, said relief member having an axialpassage therethrough, a plurality of wires extending through saidpassage, each of said Wires having an insulating covering, the outer endof each of said wires being folded back to engage the bottom surface ofone of said grooves, a collar encircling said annular portion andengaging said insulating covering of said wires to hold said wires inengagement with said body member, and said body member and said strainrelief member having means cooperating to hold said members in assembly,and said strain relief member having elements gripping said wires tominimize a pull-strain thereon, said strain relief member and saidcollar cooperating to hold the wires firmly in said grooves, saidgrooves being of greater dimensions than said wires and being adapted toreceive a mating contact and for making electrical connection therewithby removal of the insulation from the wires upon movement of the matingcontact .into the grooves.

2. The device of claim 1 in which said strain relief member has aplurality of flexible portions gripping said wires, said body memberhaving a constricted portion adjacent said opening therethrough, saidconstricted portion engaging said flexible portions when said bodymember and strain relief member are in assembly to hold said flexibleportions in gripping relation to said wires.

3. The device of claim 1 in which said strain relief member is oftubular form and provides a series of flexible portions extendingaxially thereof at its forward end, each of said flexible portionshaving an inwardly disposed gripping element extending into saidpassage, and said body member having walls adjacent said openingconverging forwardly thereof, said converging walls engaging saidflexible portions when said body member and strain relief member are inassembly to hold said flexible portions in gripping relation to saidwires.

4. A plug member for an electrical connector comprising a body memberhaving an opening therethrough, said body member having an annularportion at its rearward end, said annular portion having a series ofaxially extending grooves in its outer surface extending from itsrearward end toward its forward end, a strain relief member disposedwithin said opening, said relief member having an axial passagetherethrough, a plurality of wires extending through said passage, eachof said wires having an insulating covering, the outer end of each ofsaid wires being folded back to engage the bottom surface of one of saidgrooves, fastener means associated with said annular portion for holdingsaid wires in engagement with said body member, and said body member andsaid strain relief member having means cooperating to hold said membersin assembly, and said strain relief member having elements gripping saidwires to minimize a pull-strain thereon, said strain relief member andsaid fastener cooperating to hold the wires firmly in said grooves, saidgrooves being of greater dimensions than said wires and being adapted toreceive a mating contact and for making electrical connection therewithby removal of the insulation from the wires upon movement of the matingcontact into the grooves.

References Cited by the Examiner UNITED STATES PATENTS 2,359,570 10/1944McLarn 33999 X 2,593,743 4/1952 Galvao 33997 2,801,396 7/1957 Stegeman33997 3,012,219 12/1961 Levin et a1 33998 3,027,536 3/ 1962 Pasternak33997 3,142,524 7/ 1964 McDonough 33998 20 EDWARD C. ALLEN, PrimaryExaminer.

W. DONALD MILLER, Examiner.

1. A PLUG MEMBER FOR AN ELECTRICAL CONNECTOR COMPRISING A BODY MEMBERHAVING AN OPENING THERETHROUGH, SAID BODY MEMBER HAVING AN ANNULARPORTION OF REDUCED DIAMETER AT ITS REARWARD END, SAID ANNULAR PORTIONHAVING A SERIES OF AXIALLY EXTENDING GROOVES IN ITS OUTER SURFACEEXTENDING FROM ITS REARWARD END TOWARD ITS FORWARD END, A STRAIN RELIEFMEMBER DISPOSED WITHIN SAID OPENING, SAID RELIEF MEMBER HAVING AN AXIALPASSAGE THERETHROUGH, A PLURALITY OF WIRES EXTENDING THROUGH SAIDPASSAGE, EACH OF SAID WIRES HAVING AN INSULATING COVERING, THE OUTER ENDOF EACH OF SAID WIRES BEING FOLDED BACK TO ENGAGE THE BOTTOM SURFACE OFONE OF SAID GROOVES, A COLLAR ENCIRCLING SAID ANNULAR PORTION ANDENGAGING SAID INSULATING COVERING OF SAID WIRES TO HOLD SAID WIRES INENGAGEMENT WITH SAID BODY MEMBER, AND SAID BODY MEMBER AND SAID STRAINRELIEF MEMBER HAVING MEANS COOPERATING TO HOLD SAID MEMBERS IN ASSEMBLY,AND SAID STRAIN RELIEF MEMBER HAVING ELEMENTS GRIPPING SAID WIRES TOMINIMIZE A PULL-STRAIN THEREON, SAID STRAIN RELIEF MEMBER AND SAIDCOLLAR COOPERATING TO HOLD THE WIRES FIRMLY IN SAID GROOVES, SAIDGROOVES BEING OF GREATER DIMENSIONS THAN SAID WIRES AND BEING ADAPTED TORECEIVE A MATING CONTACT AND FOR MAKING ELECTRICAL CONNECTION THEREWITHBY REMOVAL OF THE INSULATION FROM THE WIRES UPON MOVEMENT OF THE MATINGCONTACT INTO THE GROOVES.